The Brain Tumor Epidemiology Consortium (BTEC) Meeting is an open meeting scheduled for September 26, 27 2005 in Chicago, Illinois at the University of Illinois at Chicago School of Public Health on 1603 West Taylor Street with the intent to bring together senior and junior investigators in brain tumor epidemiology and neuropathology for the purpose of addressing issues current and future directions of diagnostic and classification markers in brain tumors as they relate to epidemiologic research. It is anticipated that an open multidisciplinary discussion will allow participants to develop a consensus on systematic approaches for conducting pathology reviews as necessary to proceed with pooling data from several studies as planned by these scientists. It is essential that both epidemiology and neuropathology expertise are available to guide these discussions and that ongoing projects frame the issues and solutions in this discussion BTEC has recognized that a major strength of a consortium is their potential to conduct pooled studies of rare tumors such as those found in the brain. The epidemiology of brain tumors lags behind the progress made in other cancers and made in the clinical and biological sciences of brain tumors in the 1990s. This lack of progress partially reflects the difficulty of accruing information on adequate numbers of brain tumors in an unbiased fashion and the difficulty of attracting individuals and major research dollars to study rare and relatively fatal tumors. Tumor classification issues could preclude pooled tumor-specific studies from being performed because of a lack of consensus among neuropathologists for some brain tumor types. Multi- institutional studies can solve the study size issues, but quality controls reviews of pathology materials have become increasingly difficult since HIPAA regulations have been passed. This meeting will bring together neuro-pathologists and epidemiologists to address these issues as they pertain to BTEC projects.